Air temperature control system



March 1970 HANSLUDW!G voN CUBE 3,500,897

AIR TEMPERATURE CONTROL SYSTEM 2 Sheets-Sheet 1 Filed May 20, 1968 March 1970 HANS-LUDWIG VON CUBE 3,500,897

AIR TEMPERATURE CONTROL SYSTEM Filed May 20, 1968 2 SheetsSheet 2 I v NTO am MC/flu $1 M;

I w! F7 United States Patent 3,500,897 AIR TEMPERATURE CONTROL SYSTEM Hans-Ludwig von Cube, Worms (Rhine), Germany, as-

signor to Robert Bosch Hauserate G.m.b.H., Giengen, Germany Filed May 20, 1968, Ser. No. 730,391 Claims priority, application Germany, June 1, 1967, 1,551,286 Int. Cl. 9b 29/00 US. Cl. 16526 11 Claims ABSTRACT OF THE DISCLOSURE The steam of a heated medium is supplied by operation of a valve, either to a condenser whose condensate is supplied to one or two heat exchangers for cooling air, or directly to the heat exchangers for heating air. During the cooling operation, the steam of the medium passes through a steam jet compressor which provides suction for returning the evaporated condensate from the heat exchangers to the steam jet compressor. During heating, the condensate produced in the heat exchangers, during cooling, the condensate produced in the liquefying condenser, is pumped back into the steam generator in which steam of the medium is formed, preferably by the heat of exhaust gases of an engine so that a motorcar can be heated or cooled.

BACKGROUND OF THE INVENTION The present invention relates to an air temperature control system which is particularly suited for a motorcar whose engine produces exhaust gases for heating a steam generator which transforms a working medium into steam which is supplied to a steam jet compressor.

It is known that steam jet cooling apparatus is successfully operated where heat energy is inexpensively available, for example in the form of exhaust gases of a combustion engine. Cooling apparatus of this type has low weight and requires little service so that it is particularly suitable for cooling the storage chamber and the load of large refrigerated trucks. Occasionally, steam jet cooling apparatus is also used in combined air temperature control systems in which they are used for cooling purposes, while additional heating apparatus and heat exchangers are provided for heating the air, when required.

SUMMARY OF THE INVENTION It is one object of the invention to provide an air temr perature control system of simple and efiicient construction which can be used for cooling and heating air.

Another object of the invention is to provide an air temperature control system in which steam of a working medium, produced in a steam generator, is either used for operating a steam jet compressor connected with a liquefying condenser for cooling purposes, or is supplied to a heat exchanger for heating purposes.

Another object of the invention is to provide an air temperature control system with valve means by which a heat exchanger can be selectively connected with hot steam or a cold liquid condensate of a medium for heating or cooling the air.

Another object of the invention is to provide an air temperature control system for a motorcar including a steam generator for a medium heated by the exhaust gases of the engine of the motorcar.

Another object of the invention is to provide an air temperature control system for cooling and heating air without the use of a heater.

With these objects in view, an air temperature control 3,500,897 Patented Mar. 17, 1970 system according to the invention comprises a steam generator including means for heating a heat transferring working medium so that the same leaves the outlet of the steam generator in the form of steam; heat exchanger means in contact with air; steam conduit means connected with the outlet of the steam generator and including a steam jet compressor; condenser conduit means connecting the steam conduit means with the heat exchanger and including condenser means for supplying a condensate to said heat exchanger means; and valve means in the steam conduit means having a plurality of cooling positions connecting the steam conduit means with the condenser conduit means and connecting the suction inlet of the steam jet compressor with one or several heat exchangers, and a heating position disconnecting the steam conduit means from the condenser conduit means and connecting the steam conduit means with the heat exchanger means. In the cooling positions of the valve means, air passing through the heat exchanger means is cooled, and in the heating position, air passing through the heat exchanger means is heated. Consequently, by shifting the valve means, the apparatus can be placed in cooling and heating positions.

If the air temperature control system is provided in a motorcar, for example a truck with a food storage compartment, the exhaust gas of the engine flows through the steam generator and provides the heat for heating the medium, and for transforming the same into steam.

The medium flows in the heat generator through a tube into which condensate is pumped which is then transformed into steam.

The condenser conduit means preferably include a collector vessel for the condensate which is connected with the pump. A condensate conduit connects the collector vessel with the heat exchanger means so that the suction in the suction conduit means draws the condensate into the heat exchanger means.

Another condensate conduit connects the heat exchanger with the collector vessel so that condensate flows into the same during a heating operation when steam of the medium is directly supplied to the heat exchanger means and condensed in the same.

In one embodiment of the invention, a valve connects the steam outlet of the steam generator selectively with the steam jet compressor or with the suction conduit.

In another embodiment of the invention, a plurality of heat exchangers are provided, and a valve having several positions selectively connects the suction inlet of a steam jet compressor to two heat exchangers for receiving a condensate from a condensate collecting vessel so that both heat exchangers cool the air, or connect one heat exchanger to the steam conduit means, and the other to the suction port, or connect both heat exchangers with the steam conduit means so that the temperature of the air passing through the heat exchangers can be adjusted as desired.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic schematic view illustrating a first embodiment of the invention in which a single heat exchanger is used for cooling or heating air; and

FIG. 2 is a diagrammatic schematic view illustrating a preferred second embodiment of the invention provided vith two heat exchangers which can be selectively heated 1r cooled for varying the temperature of the air flowing herethrough.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Refering first to FIG. 1, a steam generator 1 is conlected with a pipe 2 to which the hot exhaust gases of L combustion engine are supplied for heating a heat transerring working medium, such as which is supplied to tube t as a condensate in liquid form through a return conluit 17, and leaves the outlet of tube 3 as steam. The :xhaust gases flow in countercurrent to the medium in ube 3, as indicated by the arrow A.

A steam conduit 4a connects the outlet of tube 3 with he inlet of a steam jet compressor 5, and connects the ame with a condenser 6 which is cooled by air so that a iquid condensate is formed of the medium in condenser i. A valve 4 is provided in the steam conduit 4a and has position connecting steam jet compressor 5 with the outet of tube 3, and another position disconnecting the steam at compressor.

Assuming that the apparatus is provided on a motorcar r truck, the air flow along the moving car can be guided u the direction of the arrow B through condenser 6 to iquefy the medium. However, any other cooling source an be used instead of the air flow in condenser 6.

The condensate flows through a condenser conduit 7 vnd a check valve 8 into a collector vessel 9 from where art of the condensate is pumped by pump 16 and return onduit 17 into the inlet of the pipe 3.

Due to the flow of steam through the steam jet comressor 5, suction is produced in the suction conduit 14, 5 which is connected with the heat exchanger 13 so that ondensate from collector vessel 9 is also sucked through ondensate conduit 10 and the regulating valve 11 into he heat exchanger 13 where the condensate is vaporized y heat transferred from the air flowing in the direction f the arrow C through the heat exchanger 13, while the ir is cooled. The air stream C is formed by the air IhOSB temperature is to be controlled. The medium vapoized in heat exchanger 13 is sucked through suction conuit means 14 and 15 into the steam jet compressor 5 and ecirculated. Regulating valve 11 is controlled by a sensor 2 in the region of suction conduit 14 so that regulating alve 11 opens when the temperature sensed by sensor 12 1 suction conduit 14 corresponds to the temperature of a aporized condensate. The vaporized condensate returned 3 steam jet compressor 5 is again compressed and applied to the liquefying condenser 6.

When it is desired to heat the air stream C instead of ooling the same, valve 4 is turned to its other position iterrupting the flow of steam from the outlet of pipe 3 the inlet of the steam jet compressor, and connecting 1e steam conduit portion 4b with the steam outlet so lat steam flows through valve 4, conduit portion 4b, and lrough conduit 14 into heat exchanger 13. Since steam at compressor 5 is disconnected by valve 4, no suction applied to conduit 14 in the shifted position of the alve.

The hot steam of the medium transfers heat to the air ow C which is heated while the medium is condensed nd flows through a condensate conduit 18 and a check alve 19 into the condensate collector vessel 9 from where is pumped by pump 16 through return conduit 17 into ipe 3 of the steam generator 1. No condensate is supplied trough condensate conduit 10 into the heat exchanger 13, nce sensor 12 senses the high temperature of the steam swing through conduit 14, and closes the regulating alve 11.

By shifting valve 4 between a cooling position and a eating position, the same heat exchanger 13 can be used r cooling or heating, respectively, the air flow C of the :mperature controlled air.

In the embodiment of FIG. 2, parts which correspond 4 to like parts in FIG. 1 are indicated by the same reference numerals. A pump 16 pumps the condensate of the medium from a condensate collector vessel 9' into the inlet of a pipe 3 through which the heat transferring medium flows, and the heat of exhaust gases flowing in the direction of the arrow A through the steam generator 1, heats the medium to a temperature in which it is transformed into steam which is directly supplied through the steam conduit 40 in which the steam jet compressor 5 is located.

A heat exchanger 13 corresponding to heat exchanger 13 of the embodiment of FIG. 1, is connected by a conduit 10 having a regulating valve 11 to the collector vessel 9, and connected by a connecting conduit 14a to a control port 25 of a control valve means 20. A sensor 12 determines the temperature in conduit 14a and controls regulating valve 11 accordingly. Heat exchanger 13 is also connected by a condensate conduit 18 and a check valve 19 to the collector vessel 9'.

In the embodiment of FIG. 2, a second heat exchanger 13' is provided and connected by a suction conduit 14' to the control port 26 of valve means 20. The air to be cooled or heated passes in a stream first through heat exchanger 13, and then through heat exchanger 13'. A condensate conduit 18 having a check valve 19' connects heat exchanger 13 with collector vessel 9'.

A condensate conduit 7 connects condenser 6 through a check valve 8 with collector vessel 9', and the portion 7a of condenser conduit 7 connects condenser 6 with the port 23 of valve means 20.

Valve means 20 has a pressure port 22 connected by steam conduit 40 to steam jet compressor 5, and a suction port 24 connected by suction conduit 15 to steam jet compressor 5.

A valve member 2i is movably mounted in the valve housing in which pressure port 22, suction port 24, and control ports 26, 25 and 23 are provided, and has closing portions 21a, 21b and 210, and passages 21d and 21e. Valve member 21 can be shifted in the valve housing by a manual operation, or under the control of an adjustable thermostat which senses the temperature of the air to be cooled or heated flowing in the stream C through heat exchangers '13 and 13'.

In the illustrated position of valve member 21, the medium passing through the steam jet compressor 5, flows through ports 22, 23, and passage 21d into condenser 6 in which it is liquefied and flows as a condensate through condenser conduit 7 and check valve 8 into collector vessel 9. Air flow B along the moving motorcar, or any other forced ventilation receives the heat from the medium passing through condenser 6.

Since suction conduit 15 is connected through ports 24, 25 and passage 2le with suction conduit 14a, condensate is sucked through heat exchanger 13 and conduit 10 out of collector vessel 9'.

Since suction conduit 15 is also connected through ports 24, 26 and passage 21:: with suction conduit 14, condensate is sucked through heat exchanger 13 and conduit 18' out of collector vessel 9 so that the air stream C, which first flows through heat exchanger 13 and then through heat exchanger 13, is cooled in both heat exchangers.

The sensor 12 senses the temperature of the medium flowing through conduit 14a and opens regulating valves accordingly. Another sensor, not shown, may cooperate with suction conduit 14 to control regulating valve 11'. The evaporated medium flows through conduit 15 into the steam jet compressor 5, is compressed by the steam supplied through conduit 40 to steam jet compressor 5, is liquefied in condenser 6, and condensate is collected in collector vessel 9. Part of the condensate, however, is pumped from collector vessel 9' into tube 3 where it is transformed into steam for operating the steam jet compressor.

If the temperature of the cooled air stream C becomes too low, valve member 21 is shifted to a second position in the direction of the arrow W. In this second position, valve portion 21b closes port 26 so that suction conduit 14' and heat exchanger 13 are disconnected, and only heat exchanger 13 is used for cooling the air flow C, as described above. Consequently, the air is cooled to a lesser degree.

When valve member 21 is shifted to a third position, valve portion 21b opens port 26 so that the same is connected by passage 21d with pressure port 22 which communicates with the outlet of the steam jet compressor 5. The connection between ports 24 and 25 is maintained by passage 21e so that heat exchanger 13 remains operative for cooling the air flow C. However, the hot steam supplied by steam jet compressor 5 through ports 22, 26, passage 21d, and conduit 14 to heat exchanger 13', is liquefied therein to heat the air flow C passing heat exchanger 13. Consequently, the air C is first cooled and thereby dried in heat exchanger 13, and then again heated in heat exchanger 13.

The condensate forming in heat exchanger 13 flows through condensate conduit 18 into collector vessel 9.

When valve member 21 is shifted in the direction of the arrow W to a fourth position, port 22 remains connected by passage 21d and port 23 with condenser conduit 7a, and by passage 21d and port 26 with heat exchanger 13', as in the third position. Valve portion 21b closes ports 24 and 25 so that heat exchanger 13 is disconnected and has no cooling effect. Heat exchanger 13 receives the hot steam from steam jet compressor 5, as in the preceding position, so that the air flow C is heated by heat exchanger 13'.

When valve member 221 is shifted to a fifth position, it is stopped by a stop, not shown. In the fifth position, the valve portion 21a of valve member 21 completely closes port 23 so that condenser conduit 7, 7a and condenser 6 are disconnected from steam jet compressor 5. Valve portion 21!) moves to the position in which valve portion 210 is shown in FIG. 2, and the hot steam flowing from steam jet compressor 5 into port 22, flows through passage 21d and ports 25 and 26 into conduits 14 and 14a and from the same into heat exchangers 13' and 13. Both heat exchangers transfer heat to the air flow C so that the same is rapidly heated. The condensate formed in heat exchangers 13 and 13 flows through condensate conduits and 18 into collector vessel 9. Pump 16 pumps the condensate from collector vessel 9 through return conduit 17 into the inlet of the pipe 3 where the medium is transformed into steam.

In the embodiment of FIG. 2, the shifting of a single valve, by a manual operation or by an automatic thermostat operation, effects diiferent degrees of heating and cooling, and also drying of the heated air.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of air temperature control systems differing from the types described above.

While the invention has been illustrated and described as embodied in an air temperature control system employing a steam jet compressor and valve for heating and cooling air to different temperatures, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

What is claimed is:

1. Air temperature control system, comprising, in combination, a steam generator having an inlet and an outlet for a medium, and including means for heating said medium so that the same leaves said outlet in the form of steam; heat exchange means including a plurality of heat exchangers in contact with air whose temperature is to be controlled; steam conduit means connected with said outlet and including a steam jet compressor having a suction inlet; condenser conduit means connectingsaid steam conduit means with said heat exchangers and including cooled condenser means for supplying a condensate to said heat exchangers; suction conduit means including a plurality of suction conduits connecting said heat exchangers, respectively, with said steam jet compressor; and valve means in said steam conduit means having a plurality of cooling positions connecting said outlet and said steam conduit means with said condenser conduit means so that air is cooled by the condensate supplied to said heat exchangers, and selectively connecting said suction inlet with one suction conduit and heat exchanger and with a plurality of suction conduits and heat exchangers, respectively, and a heating position disconnecting said steam conduit means from said condenser conduit means and connecting said steam conduit means with said heat exchanger means so that air is heated by the same.

2. Air temperature control system as claimed in claim 1 including pump means connected with said condenser means and with said inlet of said steam generator for supplying condensate to the latter.

3. Air temperature control system as claimed in claim 1 wherein said valve means in said heating position connects said steam conduit means with said suction conduit means and through the same with said heat exchanger means.

4. Air temperature control system as claimed in claim 1 wherein said condenser conduit means include a collector vessel for the condensate connected with said condenser means, and a condensate conduit connecting said vessel with said heat exchanger means for supplying condensate to the latter due to the suction produced in said suction conduit means and said heat exchanger by said steam jet compressor; and return conduit means connecting said collector vessel with said inlet and including a pump means for supplying condensate to said steam generator.

5. Air temperature control system as claimed in claim 4 and including a condensate conduit means connecting said heat exchanger means with said collector vessel so that condensate flows into the same while said valve means is in said heating position and steam is supplied to said heat exchanger.

6. Air temperature control system as claimed in claim- 4 including a regulating valve in said condensate conduit, and sensor means for sensing the temperature of the medium in said suction conduit means and controlling said regulating valve; and wherein said valve means in said heating position connects said steam conduit means with said suction conduit means and through the same with said heat exchanger means so that the temperature of said suction conduit means indicates whether steam or liquid condensate is supplied to said heat exchanger means.

7. Air temperature control system as claimed in claim 1 wherein said valve means has a plurality of heating positions for connecting said steam conduit means selectively with one heat exchanger, and a-plurality of said heat exchangers, respectively.

8. Air temperature control system as claimed in claim 7 wherein said valve means has a first valve portion located between said steam conduit means and said condenser conduit means and being operable for connecting and disconnecting the same in said cooling and heating positions, and a second valve portion movable between 'a plurality of positions for selectively opening and closing said suction conduits. f

9. Air temperature control system as claimed in claim 8 wherein. said suction conduit means includes a conduit portion connected with said suction inlet and said plurality of suction conduits; and wherein said valve means includes a valve housing having port s communicating with said steam conduit means and with said conduit portions, and other ports respectively communicating with said suction conduits and with said condenser conduit means, and a valve member operable between a plurality of positions for establishing and interrupting communication between said ports, so that in a first position of said valve member steam is supplied to said condenser means and evaporated condensate is sucked from said heat exchangers into said steam jet compressor, in a second position evaporated condensate is sucked from one of said heat exchangers, in a third position evaporated condensate is sucked from one ofsaidheat exchangers and the other heat exchanger receives, steam firom said steam conduit means, in a fo urth position said one heat exchanger is disconnected, and the other receives steam, and in a fifth position steam is supplied to two heat exchangers, and no steam is supplied to said condenser means.

10. Air temperature control system as claimed in claim 1 wherein said pluralityof heat exchangers are positioned relativeto each other so that the air whose temperature is to Ibe-controlled successively passes and contacts said heat exchangers.

11. Air temperature control system, comprising,. in combination, ;a steam generator; a steam jet compressor connected with said steam generator and having a discharge outlet and a suction inlet; first and second heat exchangers in contact with air whose temperature is to be controlled; condenser conduit means including cooled condenser means for supplying a condensate to said heat exchangers; and valve means having a pressure port and a suction port connected with said discharge outlet and with saidsuction inlet of said steam jet compressor, respectively, first and second control ports connected with said first and second heat exchangers, respectively, and a third control port connected with said condenser means, and including a valve member movable between first, second, and third cooling positions in which said pressure port is connected with said condenser means, said valve member connecting in said first cooling position said suction port with said first and second control ports and said first and second heat exchangers, connecting in said second cooling position said suction port with said second control port and second heat exchanger only, while closing said first control port, and connecting in said third cooling position said pressure port with said first control port and first heat exchanger, and said suction port with said second control port and with said second heat exchanger, said valve member being also movable between a first heating position connecting said pressure port with said first control port and first heat exchanger and with said third control port and condenser means, and closing said second control port and suction port, and a second heating position closing said third control port .so that said condenser is disconnected, and connecting said pres sure port with said first and second control ports and with said first and second heat exchangers.

References Cited UNITED STATES PATENTS 1,993,300 3/1935 Raudel 62116 2,114,316 4/1938 Raudel 165-62 2,327,451 8/ 1943 Perrine 165-62 2,500,202 3/1950 Powers 62-191 WILLIAM J. WYE, Primary Examiner US. Cl. X.R. 

